reproduce (this is a W=1 build):
        git checkout v6.12
        b4 shazam https://lore.kernel.org/r/20241122074612.1582161-1-lizhijian@fujitsu.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um SUBARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash